Plants and animals in NSW wetlands

Wetlands are home to a diverse range of plants, birds, fish, frogs, reptiles and mammals. This wildlife lives in a range of wetland types, including floodplain wetlands such as the Macquarie Marshes, coastal wetlands such as Myall Lakes, hanging swamps and upland swamps on the tablelands, and sphagnum bogs in the Snowy Mountains.

The breeding cycles of many animals are tied to the regular, natural flooding of wetlands. Colonial nesting waterbirds require large floods to support regular breeding and migratory waterbirds use a range of wetlands to rest, feed and breed during their annual long journeys. Coastal wetlands provide refuge for many waterbirds during droughts in inland NSW and provide nurseries for many types of fish. Hanging swamps and upland swamps are used by rare animals such as the Blue Mountains water skink and corroboree frogs in the Snowy Mountains.

Regular, large flooding events in floodplain forests also enable river red gums to reproduce, and need to be spaced two to three years apart to ensure that seedlings become established. Flooding also replenishes underground water sources for the forests.

In regulated rivers, environmental water is managed to provide sufficient water to enable fish, birds and frogs to breed and plants such as river cooba, lignum and river red gums to regenerate.

Plants

There are several hundred plant species in NSW wetlands, including mosses, herbs, ferns, rushes, sedges, grasses, reeds, shrubs and trees. Wetland plants are adapted to a wetland’s hydrological regime. Some plants require wetting and drying cycles to reproduce, such as river red gums. Other plants require a constant supply of water to survive, such as aquatic plants like sedges and rushes, marine plants like seagrasses, and cool climate plants like mosses.

Birds

Many birds rely on wetlands in NSW for all or part of their life cycle. Wetlands provide habitats and food sources for birds to live and reproduce, and permanent wetlands provide a drought refuge for many species when wetlands in inland NSW are dry for long periods.

Birds that live in and rely on wetlands are called waterbirds. Waterbirds are birds which depend on free-standing water to feed by swimming, wading or diving, or for the provision of nesting sites. These include waterfowl (ducks, geese, swans), grebes, pelicans, cormorants, crakes, rails, ibis, egrets, herons and shorebirds (or waders).

Fish

Fish rely on wetlands for breeding, feeding or shelter. Many species of marine fish rely on coastal wetlands to breed and nurture their young before returning to the open ocean. Inland rivers and wetlands in NSW support iconic fish like the Murray cod.

In NSW, freshwater rivers and wetlands are home to 49 native fish species ranging from carp gudgeons about 5 cm long to the iconic Murray cod, which can grow up to 1.8 m in length and weigh up to 114 kg. Species that regularly inhabit freshwater wetlands of NSW include carp gudgeons, golden perch, Australian smelt, bony bream, Murray Darling rainbowfish and unspecked hardyhead.

Frogs

While frogs - more than any other terrestrial animal - need water to survive and breed, not all frogs are found in wetlands. Of the 71 frogs known from NSW, 47 species are dependent on wetlands, while another 14 species are known to occur in rivers. Common wetland frogs include the striped marsh frog, brown-striped grass frog, spotted grass frog, green tree frog, and red-eyed green tree frog.

Most wetland frogs have very limited tolerances for drying. Particularly in inland wetlands in NSW, where water can be either scarce for years or suddenly abundant, frogs depend on the flooding of wetlands to successfully breed.

Reptiles

Many reptiles are dependent on NSW wetlands, including water skinks, freshwater turtles, water dragons and snakes. Some reptiles such as freshwater turtles live in wetlands for a large part of their life cycle, while others such as water skinks and snakes rely on wetlands some of the time and spend the rest of their lives on dry land, usually quite close to streams or open water.

Mammals

While a visitor to a wetland in NSW might not expect to see furred animals living in the water, there are at least nine species of mammal that rely wholly or partly on NSW wetlands. Native mammals that are dependent on wetlands for all or much of their life cycle include the common water rat, platypus, fishing bat and swamp rat. Other mammals that live around wetlands include the yellow-footed antechinus, common planigale, common blossom bat, eastern chestnut mouse, and pale field rat.